My horn relay on my 70 cutlass has no power going to it ( checked with test light) and car will not start, if I hook a jumper wire from battery to relay, car will start. working on this car a long time, rebuild whole car. car was a basket case. is there supposed to be a power wire coming from the battery straight to the horn relay? my battery only has one wire coming from the + and it goes to the starter! Thanks

 

There should be a small wire to the relay.

 

There should be a wire from the + terminal of the battery to that post on the horn relay, and another wire from the BATT terminal on the alternator to that post on the horn relay also.

 

Thanks, that is what I was hoping, will get that hooked up today. I thought there is to be 4 red wires on that post, and I only had 3.

 

The number of wires running to the post depends on the optional equipment you have. There are the two feed wires I mentioned above, one from the battery and one from the alternator. There is also a red wire that runs from the horn relay post to the firewall connector, where it feeds the ignition switch, fuse panel, and headlight switch. This wire is a fusible link, by the way. Finally, there is a sense wire from the voltage regulator to the horn relay post. This wire tells the regulator what the voltage is to allow it to control to 13.8V. These are the four wires on that post with base equipment. If you have A/C, or power windows or seats, there can be additional feed wires running to that post as well.